The bounce of a squash ball changes so dramatically with surface temperature that squash, unlike other ball sports, needs a line of balls which bounce well at different surface temperatures. This allows all players the opportunity to play with a "good bounce".
If everyone uses a Pro, a good bounce is generally reserved for advanced players. Everyone else ends up somewhere on the low bounce curve. The lower the surface temperature, the lower the bounce; and the bounce can get really low.
Lowering the bounce as skill decreases imposes an escalating barrier which must be overcome in order to rally. Lesser skilled players not only have less skill, they must play a more difficult version of the game. That barrier need not exist, and disappears when bounce is approximated.
I think approximating bounce is a good thing, but understand that many players who currently play on the low bounce curve will prefer to continue. I think that's fine. Squash is what you make it, and there's room for everyone. What I think is most important is that players on the low bounce curve know they have the option to approximate bounce, and that option does not change the game of squash, it keeps it from being changed.